The scenario

Just retrofitted two 4 ton climatemaster split units
Geo pumps are in crawl
I have two electric water heaters on main level one 50g, one 80g
I live in Indiana
House of 6 people (around 6000 sf)

I am ready to connect the DSH's (both geo pumps have one)

What to do?

1.  Connect both directly to a Hot water tanks (not the right choice from what i have read)
2. Connect both to a single storage tank (serial plumbed with check valves) that will feed both hot water heaters (leaning toward this with an 80g storage tank)
3.  Connect each DSH to it's own storage tank.


Any issues I need to consider other than fit when putting a storage tank/s in the crawl??
I assume 80 gallon is the right size if it is hooked up to both DSH's.
How about a short fat 80 gallon tank that would fit well in my crawl,  (no room in house and no room in garage)?  Any manufacterer, model numbers etc.?

Thanks in advance,

Steve

Don't know how deep the crawl is, but a couple of lowboy 50s might fit better and cost less. Might plumb one to each finish tank. Not really enough info to offer more (i.e. distance from finish tanks, usage of each tank etc.). No advice from your installer?

Crawl is clean and dry. About 40 inches deep. Distance from Geo units to 50 gallon tank is 10 feet, distance to 80 gallon tank is around 50 feet.

No advice from your installer?

I'd been considering a similar problem. My thought was that it'd be better to plumb both DSH to one larger common tank, since the two units serve different sections of house which will have very different run times based on season and sun.

Installer with no advice. I have the climatemaster manual. It says min 50 gallon and gives a good schematic. There is no discussion in manual of this situation with two pumps (with dsh) and two water heaters.

Both DSH's into one storage tank. I am a big fan of smaller buffer tanks for quicker recovery, but with 6 water users and 8 tons capacity, you are getting in the range where 80 gallons might work good as well. Normally I have had up to 30 ton DSHs on a 50 gal buffer tank. Lesser hot water user's though.

http://welserver.com/WEL0424/

Thanks for the replies

From a space standpoint (ht of crawl), I would be limited to 50 gal low boys. Would one 50 gallon tank connected to both DSH be preferable to two? Or is it too small to take advantage of the available BTU's?

Also, I am intrigued by the concept of 80 gal tank on its side, anybody with any experience here?

Steve H

50 gal is plenty of volume for (2) 4 ton heat pumps. In my opinion, volume is not as important as temperature and response time for the buffer tank. To ensure that the water in the buffer tank feeding the second tank is as warm as possible, do make the buffer tank too large, otherwise the second tank's electric heat element will have to make up the difference. The second tank should be sized according to your hot water needs. 4 or more hot water users we usually go with a 80 gal tank.